Experiments Ring the ‘Death Knell’ for Sterile Neutrinos
Neutrino detectors rely on photomultiplier tubes such as this one from the Miniboone experiment.
中微子探测器依赖于光电倍增管，例如 Miniboone 实验中的光电倍增管。
Neutrinos have about as little influence as a particle can have.
中微子的影响力与粒子的影响力一样小。
They have essentially no heft, no electric charge, and no “color” charge.
它们基本上没有重量，没有电荷，也没有“色”电荷。
As a result, the neutrino has no connection with most of nature’s forces; it can slip through whole planets and stars without striking a single atom.
因此，中微子与大多数自然力没有联系。它可以穿过整个行星和恒星而不撞击任何一个原子。
But neutrinos have proven more than capable of bending the life path of a scientist.
但事实证明，中微子不仅能够改变科学家的人生道路。
In the late 1990s, when physicists unexpectedly discovered that neutrinos have mass, Thierry Lasserre abandoned cosmology to go all in on the particles.
20 世纪 90 年代末，当物理学家意外地发现中微子具有质量时，蒂埃里·拉塞尔 (Thierry Lasserre) 放弃了宇宙学，转而全力研究粒子。
“It was so exciting I just couldn’t resist,” said Lasserre , now a physicist at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany.
“这太令人兴奋了，我无法抗拒，”现为德国海德堡马克斯·普朗克核物理研究所的物理学家拉塞尔说。
And Mark Ross-Lonergan was planning to be a meteorologist until a chance encounter with particle physics in 2010 inspired him to switch fields.
马克·罗斯-罗纳根 (Mark Ross-Lonergan) 原本计划成为一名气象学家，直到 2010 年一次偶然接触到粒子物理学，促使他转行。
Lassere and Ross-Lonergan, along with thousands of others, have devoted their careers to investigating this tiny and almost perfectly inert speck.
拉塞尔和罗斯-洛纳根以及其他数千人将他们的职业生涯奉献给了研究这个微小且几乎完全惰性的斑点。
For more than a decade, their investigations seemed to be closing in on a breakthrough.
十多年来，他们的调查似乎即将取得突破。
Experiments reported strange acts of neutrinos appearing and disappearing.
实验报告了中微子出现和消失的奇怪行为。
These results, along with neutrinos’ mysterious mass, all pointed to a single potential explanation: A particular “sterile” type of neutrino, of a particular mass, seemed to lurk undiscovered behind the scenes.
这些结果，连同中微子的神秘质量，都指向一个潜在的解释：一种特定的“惰性”类型、具有特定质量的中微子，似乎潜伏在幕后未被发现。
Thierry Lassere, a physicist at the Max Planck Institute in Germany, has spent years looking for the electron-volt sterile neutrino.
德国马克斯·普朗克研究所的物理学家蒂埃里·拉塞尔多年来一直在寻找电子伏特惰性中微子。
The latest results from his collaboration suggest they don’t exist.
他的合作的最新结果表明它们并不存在。
Researchers spent years running increasingly sophisticated experiments to pin down the interloper.
研究人员花了数年时间进行越来越复杂的实验来确定闯入者。
However, in the face of an increasing number of null results, most notably in studies published in late 2025, most physicists now agree that this sterile neutrino doesn’t exist.
然而，面对越来越多的无效结果，尤其是在 2025 年末发表的研究中，大多数物理学家现在都同意这种惰性中微子不存在。
“This is, in my opinion, the death knell for sterile neutrinos,” said Ross-Lonergan , a physicist at Columbia University and co-author of one of the latest studies.
“在我看来，这是惰性中微子的丧钟，”哥伦比亚大学物理学家、一项最新研究的合著者罗斯-罗纳根说。
These developments have only deepened the mysteries of neutrinos.
这些进展只会加深中微子的神秘面纱。
Their apparent ability to appear in some experiments and vanish from others remains unexplained.
它们在某些实验中出现并在其他实验中消失的明显能力仍然无法解释。
And the fact that they have mass essentially requires them to be in contact with some undiscovered aspect of reality.
事实上，它们拥有质量本质上要求它们接触现实中一些未被发现的方面。
For physicists, the particle’s influence continues unabated.
对于物理学家来说，粒子的影响有增无减。
“It’s on us to learn how to get creative,” said Matheus Hostert , a physicist at the University of Iowa.
“我们有责任学习如何发挥创造力，”爱荷华大学物理学家马修斯·霍斯特特 (Matheus Hostert) 说。
“This is a very exciting time for the field, especially for theorists like myself who get to ask hard questions about all this data.”
“对于这个领域来说，这是一个非常激动人心的时刻，特别是对于像我这样的理论家来说，他们可以对所有这些数据提出尖锐的问题。”
Everything physicists know about neutrinos, they’ve learned through experiments that didn’t quite add up.
物理学家对中微子的了解都是通过实验得知的，但这些实验并不完全合理。
“The whole field is built on a backbone of anomalies,” Ross-Lonergan said.
“整个领域都是建立在异常现象的基础上的，”罗斯-罗纳根说。
Wolfgang Pauli first inferred the presence of the neutrino in 1930 from a study of radioactive decays.
1930 年，沃尔夫冈·泡利 (Wolfgang Pauli) 通过放射性衰变研究首次推断出中微子的存在。
In these decays, an atom of one element transforms into another while releasing its remaining energy in the form of an electron.
在这些衰变中，一种元素的原子转变为另一种元素，同时以电子的形式释放其剩余能量。
But in certain decays, the electron doesn’t have enough zip.
但在某些衰变中，电子没有足够的速度。
Pauli argued that some additional, invisible particle must be smuggling the leftover energy into the world.
泡利认为，一定有一些额外的、看不见的粒子正在将剩余的能量偷运到世界上。
This particle, which he called “little neutral one,” would have no electric charge and no mass.
这种粒子被他称为“小中性粒子”，不带电荷，也没有质量。
It would interact with the atoms of our world only through the weak force, which makes radioactive decay possible by turning certain subatomic particles into others.
它只能通过弱力与我们世界的原子相互作用，这使得通过将某些亚原子粒子转变为其他粒子而使放射性衰变成为可能。
Wolfgang Pauli first intuited the presence of the neutrino from the missing energy in radioactive decays.
沃尔夫冈·泡利首先从放射性衰变中缺失的能量中直觉到中微子的存在。
The weak force is so weak, however, that a neutrino could travel through light-years of lead without altering a single atom.
然而，弱力非常弱，以至于中微子可以穿过数光年的铅而不改变单个原子。
Pauli bet a case of champagne that no one would ever detect one.
泡利与一箱香槟打赌，没有人会发现它。
But some 20 years later, ingenious experimentalists caught unmistakable signs of neutrinos at the Savannah River Site nuclear power plant in South Carolina.
但大约 20 年后，聪明的实验家在南卡罗来纳州萨凡纳河核电站发现了明显的中微子迹象。
Soon after, physicists started brainstorming about what they could learn from these nigh-invisible heralds of weak force transformations.
不久之后，物理学家开始集思广益，讨论他们可以从这些几乎看不见的弱力转变先驱中学到什么。
They turned their focus from artificial nuclear reactors to a natural one — the sun.
他们将注意力从人造核反应堆转向了自然核反应堆——太阳。
In the late 1960s, Raymond Davis Jr. oversaw the installation of a 100,000-gallon tank of dry-cleaning fluid in a mine nearly a mile underground, where he planned to study solar neutrinos.
20 世纪 60 年代末，雷蒙德·戴维斯 (Raymond Davis Jr.) 在地下近一英里的矿井中监督安装了一个 100,000 加仑的干洗液罐，他计划在那里研究太阳中微子。
John Bahcall, the co-leader of the experiment, calculated the number of neutrinos the experiment should see.
该实验的共同领导者约翰·巴考尔（John Bahcall）计算了实验应该看到的中微子数量。
But the tank picked up just one-third of the number of neutrinos that Bahcall had predicted it should.
但该储罐仅捕获了巴考尔预测的中微子数量的三分之一。
Either the sun was underperforming expectations, or neutrinos were going missing.
要么是太阳表现不佳，要么是中微子失踪了。
The anomaly took 30 years to resolve.
这一异常现象花了 30 年才得到解决。
But when the resolution came, via the Super-Kamiokande experiment in Japan and the Sudbury Neutrino Observatory (SNO) in Canada, it delivered a bombshell.
但当这项决议通过日本的超级神冈实验和加拿大萨德伯里中微子天文台（SNO）得出时，它带来了一个重磅炸弹。
The cavernous neutrino detector placed in the Homestake Gold Mine near Lead, South Dakota, in the late 1960s picked up the first hints that neutrinos were oscillating from one form to another as they traveled.
20 世纪 60 年代末，放置在南达科他州利德附近霍姆斯特克金矿的海绵状中微子探测器首次发现了中微子在传播过程中从一种形式振荡到另一种形式的迹象。
Sanford Underground Research Facility
桑福德地下研究设施
Neutrinos were disappearing because they were changing form.
中微子正在消失，因为它们正在改变形式。
Neutrinos come in three varieties, dubbed electron, muon, and tau.
中微子分为三种，称为电子、μ子和τ子。
And Super-Kamiokande and SNO showed that neutrinos of one type, visible in the Davis experiment, were “oscillating” into neutrinos of another, which the Davis experiment could not see.
超级神冈探测器和 SNO 表明，戴维斯实验中可见的一种类型的中微子正在“振荡”成戴维斯实验中看不到的另一种中微子。
This finding was a major twist, because according to the Standard Model — the playbook that accounts for all the known behavior of all the known particles — neutrino oscillation was not allowed.
这一发现是一个重大转折，因为根据标准模型（解释所有已知粒子的所有已知行为的剧本），中微子振荡是不允许的。
Oscillation could take place only if the masses of the three types were different from one another.
只有当这三种类型的质量彼此不同时，振荡才会发生。
But all neutrinos were supposed to have exactly the same mass: none.
但所有中微子都应该具有完全相同的质量：没有。
That’s because the Standard Model describes a particle as a ripple traveling through a quantum field in space, and a massive particle as two overlapping ripples traveling through two fields.
这是因为标准模型将粒子描述为穿过空间量子场的涟漪，而将大质量粒子描述为穿过两个场的两个重叠的涟漪。
There’s a “left-handed” field generating particles that tend to corkscrew one way, and a “right-handed” field producing particles that tend to corkscrew the other way.
有一个“左手”场产生的粒子倾向于以一种方式呈螺旋状，而“右手”场产生的粒子则倾向于以另一种方式呈螺旋状。
The electron, for instance, has mass because it is a left-handed ripple linked with a right-handed ripple.
例如，电子具有质量，因为它是与右手波纹相连的左手波纹。
But experimentalists had seen only left-handed neutrinos, so the particle was thought to be massless — until Super-Kamiokande and SNO proved otherwise.
但实验者只看到了左手中微子，因此这种粒子被认为是无质量的——直到超级神冈和 SNO 证明了事实并非如此。
Thus the 20th-century anomalies culminated in a cliffhanger that remains unsolved: Why do neutrinos have mass?
因此，20世纪的异常现象最终导致了一个悬而未决的悬念：为什么中微子有质量？
One simple explanation is that there is a fourth type of neutrino, a ripple in a right-handed field, one almost perfectly invisible to experiments to date.
一个简单的解释是，存在第四种类型的中微子，即右手场中的涟漪，迄今为止的实验几乎完全不可见。
A bizarre quirk of the weak force is that it affects only left-handed fields; only left-handed neutrinos show up after nuclear decays.
弱力的一个奇怪之处在于它只影响左手场。核衰变后仅出现左手中微子。
So right-handed neutrinos would be completely barren of anything that would let them feel the forces of the Standard Model.
因此，右旋中微子将完全没有任何能让它们感受到标准模型力的东西。
Scientists call them sterile.
科学家称它们为不育的。
Alternatively, the left-handed neutrinos could turn out to be slightly ambidextrous and therefore capable of giving themselves mass.
或者，左手中微子可能具有轻微的灵巧性，因此能够赋予自身质量。
But this idea cracks the Standard Model in a different way, and the simplest patch is to add another slightly ambidextrous, but mostly right-handed, sterile neutrino.
但这个想法以不同的方式破解了标准模型，最简单的补丁是添加另一个稍微灵巧的、但主要是右手的惰性中微子。
Experiments at Los Alamos National Laboratory (top) and at the Fermi National Accelerator Laboratory have amassed substantial evidence that neutrinos may be oscillating over short distances, for unknown reasons.
洛斯阿拉莫斯国家实验室（上）和费米国家加速器实验室的实验已经收集了大量证据，表明中微子可能会出于未知原因在短距离内振荡。
Los Alamos National Laboratory (top); Fermilab
洛斯阿拉莫斯国家实验室（上）；费米实验室
Experiments at Los Alamos National Laboratory (left) and at Fermi National Accelerator Laboratory have amassed substantial evidence that neutrinos may be oscillating over short distances, for unknown reasons.
洛斯阿拉莫斯国家实验室（左）和费米国家加速器实验室的实验已经收集了大量证据，表明中微子可能会出于未知原因在短距离内振荡。
Los Alamos National Laboratory (left); Fermilab
洛斯阿拉莫斯国家实验室（左）；费米实验室
So the two simplest logical paths for explaining neutrino mass led to the same place.
因此，解释中微子质量的两条最简单的逻辑路径都通向同一个地方。
“The theorist in me says it’s a perfect storm and clearly sterile neutrinos exist somewhere,” Ross-Lonergan said.
“我内心的理论家说，这是一场完美的风暴，显然某个地方存在惰性中微子，”罗斯-罗纳根说。
And around of the turn of the century, a new generation of experiments uncovered a new generation of anomalies.
在世纪之交左右，新一代的实验发现了新一代的异常现象。
Almost all of them could be interpreted as hints that there should be one particular type of sterile neutrino.
几乎所有这些都可以解释为暗示应该存在一种特定类型的惰性中微子。
From 1993 to 1998, an experiment at Los Alamos National Laboratory called the Liquid Scintillator Neutrino Detector, or LSND, saw what looked like too many electron neutrinos in a beam of mostly muon neutrinos.
1993年到1998年，洛斯阿拉莫斯国家实验室进行了一项名为液体闪烁中微子探测器（LSND）的实验，在一束主要由μ子中微子组成的束中发现了看起来过多的电子中微子。
Later, the Miniboone experiment at Fermilab saw the same thing — way too many electron neutrinos .
后来，费米实验室的迷你布恩实验也看到了同样的情况——电子中微子太多了。
The LSND/Miniboone anomalies were born.
LSND/Miniboone 异常诞生了。
Also in the 1990s, physicists in Russia and Italy had put highly radioactive sources right next to huge vats of gallium, a metallic liquid that’s especially sensitive to neutrinos, to test whether the vats were working as neutrino detectors.
同样是在 20 世纪 90 年代，俄罗斯和意大利的物理学家将高放射性源放在巨大的镓桶（一种对中微子特别敏感的金属液体）旁边，以测试这些桶是否能起到中微子探测器的作用。
They were, but their counts of electron neutrinos were about 20% too low.
确实如此，但它们的电子中微子计数大约低了 20%。
This became known as the gallium anomaly.
这被称为镓异常。
A more refined experiment found further evidence for the gallium anomaly in 2022.
一项更精细的实验发现了 2022 年镓异常的进一步证据。
Janet Conrad, a physicist at MIT, collects datasets from neutrino experiments around the world and analyzes them for signs of new particles.
麻省理工学院的物理学家珍妮特·康拉德收集了世界各地中微子实验的数据集，并分析它们以寻找新粒子的迹象。
And in 2011, physicists found that they had been underestimating the number of electron neutrinos that should be produced in a nuclear reaction by a few percent.
2011年，物理学家发现他们低估了核反应中应产生的电子中微子的数量几个百分点。
This meant that every time that physicists had plunked down any type of detector outside a nuclear reactor and counted the “right” number of neutrinos in previous decades, in reality there had not been enough.
这意味着，在过去的几十年里，每次物理学家在核反应堆外放下任何类型的探测器并计算出“正确”的中微子数量时，实际上都还不够。
This discrepancy came to be known as the reactor antineutrino anomaly.
这种差异被称为反应堆反中微子异常。
All three of these signs pointed toward neutrino oscillation — neutrinos were, again, appearing and disappearing.
所有这三个迹象都表明中微子振荡——中微子再次出现和消失。
But the oscillation wasn’t happening slowly over millions of miles between the sun and the Earth.
但这种振荡并不是在太阳和地球之间数百万英里的范围内缓慢发生的。
This time, the neutrinos seemed to be changing fast enough to oscillate while crossing a room.
这一次，中微子的变化似乎足够快，足以在穿过房间时发生振荡。
How quickly neutrinos oscillate depends on the difference between the neutrino masses.
中微子振荡的速度取决于中微子质量之间的差异。
Oscillations between the three types show up mainly over miles of travel because their masses are all almost the same — nearly zero.
这三种类型之间的振荡主要出现在行驶里程上，因为它们的质量几乎相同——几乎为零。
But oscillations occurring over meters could be explained by the existence of a fourth, beefier neutrino — one quite like the right-handed variety theorists needed to account for neutrino mass in the first place.
但是，发生在数米范围内的振荡可以用第四种更强大的中微子的存在来解释——这种中微子很像右手簇理论家首先需要解释的中微子质量。
Specifically, a sterile neutrino weighing one or two electron volts, a unit of mass and energy, seemed to tie everything together.
具体来说，一个重一或两个电子伏特的惰性中微子（质量和能量的单位）似乎将一切联系在一起。
The Baksan Neutrino Observatory is housed deep under Russia’s Caucasus Mountains.
巴克桑中微子观测站位于俄罗斯高加索山脉深处。
It picked up unexpected neutrino counts using tanks of gallium, sparking the gallium anomaly.
它使用镓罐获得了意想不到的中微子计数，引发了镓异常。
Maxim Babenko/The New York Times
马克西姆·巴本科/纽约时报
“These [anomalies] were very different types of evidence, but they would all be explained by the same kind of sterile neutrino,” Lasserre said.
“这些[异常]是非常不同类型的证据，但它们都可以用同一种惰性中微子来解释，”拉塞尔说。
Scientists searched the world for this neutrino.
科学家们在世界各地寻找这种中微子。
They hunted it under the ice in Antarctica , next to nuclear reactors, and down in mines.
他们在南极洲的冰层下、核反应堆旁边和矿井里寻找它。
In 2007, German physicists shipped a 200-ton dirigible-shaped detector across the Mediterranean sea on a roundabout odyssey to a lab on the other side of the country — the Karlsruhe Tritium Neutrino Experiment, or Katrin.
2007 年，德国物理学家将一艘重达 200 吨的飞船形状的探测器穿越地中海，绕道航行运送到该国另一边的一个实验室——卡尔斯鲁厄氚中微子实验（Katrin）。
And Fermilab physicists upgraded Miniboone’s detector, launching a new experiment called Microboone.
费米实验室的物理学家升级了 Miniboone 的探测器，推出了一项名为 Microboone 的新实验。
The latest batch of results have come in.
最新一批结果已经出来了。
The hunt has come up short, leaving physicists puzzling over what to do next.
搜寻工作进展缓慢，让物理学家们对下一步该做什么感到困惑。
Back in 2000, when oscillations had proved that neutrinos have mass, Lassere had just completed his Ph.D. thesis in cosmology.
早在 2000 年，当振荡证明中微子具有质量时，拉塞雷刚刚完成了他的博士学位。宇宙学论文。
Intrigued, he dove into the neutrino world, and in 2011, he helped discover the reactor anomaly .
出于好奇，他深入中微子世界，并于2011年帮助发现了反应堆异常现象。
A few years later, he joined Katrin to hunt for sterile neutrinos.
几年后，他和卡特琳一起寻找惰性中微子。
Katrin uses its house-size detector to look for electrons released during radioactive decays of tritium atoms.
Katrin 使用其房屋大小的探测器来寻找氚原子放射性衰变过程中释放的电子。
Following in Pauli’s footsteps, scientists involved in the effort carefully tabulate the electrons’ energies to make stringent measurements of any excess energy that went into making the counterpart neutrinos.
追随泡利的脚步，参与这项工作的科学家们仔细地将电子能量制成表格，以严格测量用于制造对应中微子的任何多余能量。
The Katrin detector arrives in Karlsruhe, Germany, in 2006.
Katrin 探测器于 2006 年抵达德国卡尔斯鲁厄。
It had been built only a few hundred kilometers way, but because of its size, it had to travel by barge: down the Danube River, across the Black and Mediterranean Seas, around the Iberian Peninsula, through the English Channel, and up the Rhine.
它的建造距离只有几百公里，但由于其规模，它必须通过驳船运输：沿着多瑙河，穿过黑海和地中海，绕过伊比利亚半岛，穿过英吉利海峡，然后沿莱茵河上游。
The experiment’s main goal is to deduce the smallest amount of energy required to produce a neutrino — its resting mass.
该实验的主要目标是推断产生中微子所需的最小能量——它的静止质量。
In April 2025, after scrutinizing hundreds of millions of electrons, the collaboration found that the neutrino mass can’t exceed half an electron volt.
2025 年 4 月，在仔细检查了数亿个电子后，该合作发现中微子质量不能超过半电子伏特。
(An ordinary electron, by contrast, has a mass of around half a million electron volts.)
（相比之下，普通电子的质量约为五十万电子伏特。）
The experiment is also “a perfect tool” for searching for sterile neutrinos, Lasserre said.
拉塞尔说，该实验也是寻找惰性中微子的“完美工具”。
If those heavier neutrinos were to exist, they would sometimes pull additional energy away from the electrons.
如果这些较重的中微子存在，它们有时会从电子中夺走额外的能量。
But in an analysis published in December 2025, Katrin scientists saw no sign of a sterile neutrino with a mass of around an electron volt.
但在 2025 年 12 月发表的分析中，Katrin 科学家没有发现质量约为电子伏特的惰性中微子的迹象。
Lasserre called it “a major step that is inconsistent with this sterile neutrino idea” as an explanation for the reactor anomaly.
拉塞尔称其为“与惰性中微子想法不一致的重要一步”，作为对反应堆异常的解释。
He now suspects that the reactor anomaly arises from not knowing exactly how many neutrinos to expect, an opinion many physicists share.
他现在怀疑反应堆异常是由于不知道到底会有多少中微子引起的，许多物理学家都同意这一观点。
While discovering a sterile neutrino would have been thrilling, Lasserre said he feels grateful to at least have a sense of closure.
拉塞尔说，虽然发现惰性中微子会令人兴奋，但他很感激至少有一种结束的感觉。
“I am very happy, because we don’t have some ambiguous results,” he said.
“我很高兴，因为我们没有得到一些模棱两可的结果，”他说。
“I would not want to die and have it be completely open.”
“我不想死后让它完全开放。”
That satisfaction eludes Ross-Lonergan, who continues to puzzle over the LSND and Miniboone mysteries.
罗斯-罗纳根并没有得到这种满足感，他仍然对LSND和Miniboone之谜感到困惑。
Ross-Lonergan analyzes data from Microboone, which checks Miniboone’s work by using next-generation technology capable of tracking the subatomic fireworks neutrinos can produce.
Ross-Lonergan 分析了 Microboone 的数据，该数据通过使用能够跟踪中微子产生的亚原子烟花的下一代技术来检查 Miniboone 的工作。
“We get to take photos of individual atoms being broken apart,” Ross-Lonergan said.
“我们可以拍摄单个原子被分解的照片，”罗斯-罗纳根说。
“I never get tired of looking at them.”
“我永远不会厌倦看着它们。”
A detector filled with liquid argon represents the next-generation of neutrino-detection technology.
充满液氩的探测器代表了下一代中微子探测技术。
Here, a tank to hold and cool argon is installed at Femilab’s Microboone experiment.
在这里，Femilab 的 Microboone 实验中安装了一个用于容纳和冷却氩气的罐。
First, the Microboone collaboration counted the events where electrons (and therefore electron neutrinos) appeared, but they saw nothing out of the ordinary .
首先，Microboone 合作团队计算了电子（以及电子中微子）出现的事件，但他们没有看到任何异常情况。
Last year, they analyzed neutrinos coming from two different beams but still saw no trace of electron-volt sterile neutrinos .
去年，他们分析了来自两个不同束流的中微子，但仍然没有发现电子伏特惰性中微子的踪迹。
The Katrin and Microboone results, along with findings from other experiments and strong hints from cosmological surveys , converge to deliver a clear message: Physicists can’t explain everything with one slick idea.
Katrin 和 Microboone 的结果，连同其他实验的发现以及宇宙学调查的强烈暗示，共同传递了一个明确的信息：物理学家无法用一个巧妙的想法来解释一切。
The theory of the single electron-volt sterile neutrino is wrong.
单电子伏惰性中微子理论是错误的。
So one mystery has fractured into multiple mysteries.
于是，一个谜团就分裂成了多个谜团。
The reactor anomaly increasingly seems unrelated to neutrinos.
反应堆异常似乎越来越与中微子无关。
But the other experiments — LSND, Miniboone, and gallium — remain unexplained.
但其他实验——LSND、Miniboone 和镓——仍然无法解释。
“The significance of the signals, they’re all very large,” said Janet Conrad , a neutrino physicist at the Massachusetts Institute of Technology.
“这些信号的重要性都非常大，”麻省理工学院的中微子物理学家珍妮特·康拉德说。
“It’s not [the electron-volt sterile neutrino] for sure.
“这肯定不是[电子伏特惰性中微子]。
And so the question is: What else is it?”
所以问题是：还有什么？”
One possibility is that LSND, Miniboone, and gallium are just an unlucky alignment of mistakes and coincidences.
一种可能性是，LSND、Miniboone 和镓只是错误和巧合的不幸组合。
Anomalies in physics appear regularly , and physicists can usually trace them back to subtle systemic effects.
物理学中的异常现象经常出现，物理学家通常可以将它们追溯到微妙的系统效应。
“We tend to be very skeptical about anomalies, which I think is the healthy thing to do,” said André de Gouvêa , a theoretical physicist at Northwestern University who focuses on neutrinos.
“我们往往对异常现象非常怀疑，我认为这是健康的做法，”西北大学专注于中微子研究的理论物理学家安德烈·德·古维亚 (André de Gouvêa) 说。
Mark Ross-Lonergan, a physicist at Columbia University, has contributed to the data analysis of Microboone, an experiment designed to resolve the Miniboone anomaly.
哥伦比亚大学物理学家 Mark Ross-Lonergan 为 Microboone 的数据分析做出了贡献，这是一项旨在解决 Miniboone 异常的实验。
Courtesy of Mark Ross Lonergan
由马克·罗斯·洛纳根提供
But so far, no one has managed to cook up even a constellation of mistakes that could account for the Miniboone anomaly.
但到目前为止，还没有人能够编造出一系列能够解释 Miniboone 异常现象的错误。
“People work really, really hard to try to kill it,” Conrad said.
“人们非常非常努力地试图消灭它，”康拉德说。
The gallium anomaly remains similarly tough to explain away.
镓异常现象同样难以解释。
Another possibility is that the anomalies — either individually or collectively — do point to neutrino mischief, but not mischief of the simplest variety, caused by a single electron-volt sterile neutrino.
另一种可能性是，这些异常现象——无论是单独的还是集体的——确实表明了中微子的危害，但不是由单个电子伏特惰性中微子引起的最简单类型的危害。
Physicists don’t yet have the data or the computational power to say whether a more extended neutrino family containing two, three, or more electron-volt sterile neutrinos — or heavier sterile neutrinos weighing many electron volts — could help explain LSND, Miniboone, or the gallium anomaly.
物理学家还没有数据或计算能力来判断包含两个、三个或更多电子伏特的惰性中微子（或重达许多电子伏特的较重的惰性中微子）的更广泛的中微子家族是否可以帮助解释 LSND、Miniboone 或镓异常。
Microboone has ground left to cover.
麦克布恩还有很多工作要做。
And over the next decade, physicists will gain a deluge of data from new research, including a reactor experiment in China called JUNO, which is already operational, and a Fermilab-managed experiment in the United States called DUNE, which should begin taking data in the 2030s.
在接下来的十年中，物理学家将从新的研究中获得大量数据，包括中国的一个名为 JUNO 的反应堆实验，该实验已经投入运行，以及美国费米实验室管理的一个名为 DUNE 的实验，该实验应在 2030 年代开始获取数据。
For her part, Conrad is leading an experiment called Isodar, which will look specifically for fast neutrino oscillation caused by any number of light sterile neutrinos.
康拉德正在领导一项名为“Isodar”的实验，该实验将专门寻找由任意数量的轻惰性中微子引起的快速中微子振荡。
She hopes to have it up and running in 2028.
她希望在 2028 年建成并运行。
With this new information, physicists expect to assemble a much clearer picture of the neutrino realm.
有了这些新信息，物理学家希望能够对中微子领域有一个更清晰的认识。
“We usually get a little bit of good data or a lot of crappy data,” de Gouvêa said.
“我们通常会得到一点好的数据或大量的蹩脚数据，”de Gouvêa 说。
“So lots of good data is a new world for us.”
“因此，大量优质数据对我们来说是一个新世界。”
Whatever happens with the anomalies, the fact that neutrinos have mass means that the particles have a direct line to the unknown.
无论异常情况发生什么，中微子具有质量的事实意味着这些粒子与未知事物有直接联系。
And sterile neutrinos, if they’re out there in some detectable form, could be just the beginning.
而惰性中微子，如果它们以某种可检测的形式存在，可能只是一个开始。
Physicists know the Standard Model to be incomplete — it’s missing most of the universe’s mass , for instance.
物理学家知道标准模型是不完整的——例如，它缺少宇宙的大部分质量。
It’s just that detecting subtle new stuff among the blaring effects of known particles and forces is tough.
只是在已知粒子和力的巨大影响中检测微妙的新东西是很困难的。
Hostert, of the University of Iowa, likens it to picking out the faint hum of an air conditioner over the din of Manhattan traffic.
爱荷华大学的霍斯特特将其比作在曼哈顿喧嚣的交通中辨别出空调微弱的嗡嗡声。
But the barely interacting neutrino, and the even more bashful sterile neutrino, “offer a much quieter place” to listen, Hostert says.
但霍斯特特说，几乎不相互作用的中微子，以及更加害羞的惰性中微子，“提供了一个安静得多的地方”来聆听。
Of course, while he hopes that current and upcoming experiments will pick up on that quiet crackle, he knows they have no guarantee of success.
当然，虽然他希望当前和即将进行的实验能够捕捉到这种安静的噼啪声，但他知道它们并不能保证成功。
In the face of this uncertainty, some physicists adopt a stance of resigned acceptance.
面对这种不确定性，一些物理学家采取了听天由命的态度。
“It can be frustrating that in your lifetime you may not make a lot of progress,” de Gouvêa said.
“令人沮丧的是，在你的一生中，你可能无法取得很大的进步，”德古维亚说。
But thinking about the possible implications of anomalies can be instructive, he said, “and somehow we’re all secretly in it just to learn new stuff.”
但思考异常可能产生的影响可能具有启发性，他说，“不知何故，我们都在秘密地参与其中，只是为了学习新东西。”
Conrad, meanwhile, feels energized by the challenge.
与此同时，康拉德因挑战而感到充满活力。
She entered the field during the era of confusing anomalies that foreshadowed the discovery of neutrino mass a quarter century ago — another physicist with a life path shaped by the incorporeal particle.
她进入这个领域时正值令人困惑的异常现象时代，这一时代预示着四分之一世纪前中微子质量的发现——另一位物理学家的生命轨迹是由无形粒子塑造的。
And she thinks the field feels just as full of possibility now as it did then.
她认为这个领域现在和以前一样充满可能性。
“I think the most interesting times are the hard times,” she said.
“我认为最有趣的时刻就是艰难的时刻，”她说。
“I mean, why are you in this field, if you don’t love hard?”
“我的意思是，如果你不努力去爱，为什么还要进入这个领域呢？”
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